S2 Steel is a premium quality alloy steel for exceptional strength and durability compared with standard chrome vanadium driver bits. S2 grade hardened steel for longer life. Driver Bit Size: PH2. Length: 25mm. Shank Dia.: 1/4 inch. Shank Type: Hex. Material: S2 Hardened Carbon Steel. Please Note: Due to geographical locations we are unable to deliver to Highlands.